LCL滤波器的新型有源阻尼控制  

New Active Damping Control for LCL Filters

作　　者：付明志 王玉芝 秦猛 孟宪乐 姜齐荣[2] Fu Mingzhi;Wang Yuzhi;Qin Meng;Meng Xianle;Jiang Qirong(Tianjin Pinggao Intelligent Electric Co.,Ltd.,Tianjin 300300,China;National Key Lab. of Power System and Power Generation Equipment Control and Simulation,Tsinghua University,Beijing 100086,China)

机构地区：[1]天津平高智能电气有限公司,天津300300 [2]清华大学电力系统及发电设备控制和仿真国家重点实验室,北京100086

出　　处：《电气自动化》2019年第3期38-41,共4页Electrical Automation

摘　　要：针对光伏并网变换器所采用的LCL滤波器,首先分析了其采用三种无源阻尼方案时的频率特性。然后,根据串并联混合型无源阻尼方案系统传递函数框图变换,提出了一种采用电容电流PI反馈的新型有源阻尼控制方案。随后,利用阻抗模型研究了串联电阻无源阻尼方案、电容电流比例反馈有源阻尼方案和电容电流PI反馈有源阻尼方案对逆变器特性的影响。结果表明,电容电流PI反馈方案可以有效地增加LCL滤波器谐振频率处的阻尼,同时也增加了控制的自由度。最后,特征值分析表明新方案具有更大的控制参数稳定域,并利用PSCAD进行了仿真验证。新型有源阻尼方案不仅能够有效抑制LCL滤波器的振荡,而且与传统方案相比性能更佳,具有良好的工程实践价值。With respect to LCL filters used in photovoltaic grid connection converters,this paper firstly analyzed the frequency characteristics when three passive damping schemes were adopted.Then,according to the conversion of the block diagram of the system transfer function of the hybrid serial-parallel passive damping scheme,this paper proposed a novel active damping control scheme adopting capacitive current PI feedback.Furthermore,an impedance model was used to study the influence of passive damping scheme with serial resistor,active damping scheme with proportional feedback of capacitive current,and active damping scheme with capacitive current PI feedback upon the characteristics of the inverter.The results showed that capacitive current PI feedback scheme could effectively raise the damping at the harmonic frequencies of the LCL filter and improve the degree of freedom in the control as well.Finally,analysis of characteristic value indicated that the new scheme had a larger control parameter stability domain.Simulation verification was made in PSCAD.The new active damping scheme could not only suppress the oscillation of the LCL filter effectively,but also had a better performance than the traditional scheme.The proposed approach is of great value in engineering practice.

关 键 词：并网逆变器 LCL滤波器 无源阻尼 有源阻尼控制 参数稳定域 

分 类 号：TM72[电气工程—电力系统及自动化]